The present invention relates to a fender with a fastening end and a shock-absorbing end and, arranged therebetween, at least one deformation portion which is made of an elastically deformable material, especially elastomeric material, and which is arranged, during deformation of the fender, to fold so that surface portions of the deformation portion are folded towards each other.
Fenders of the type described by way of introduction are used on quays, oil rigs and the like.
Such fenders are known from U.S. Pat. No. 5,458,077 which describes fenders of different types, which on their inside are provided with thickenings in order to improve the rigidity of the fender.
The fender described in EP 812 961 has similarly been provided with thickenings on its outside or on the inside as well as on the outside.
U.S. Pat. No. 3,999,497 discloses a cylindrical fender which on the outside of one end has a tubular rubber element. This rubber element prevents, when subjecting the fender to loads, the fender from suddenly losing its rigidity.
EP 135 997 describes a fender which in the outer surface close to its one end is provided with a fold line (slot) to control the deformation of the fender when subjected to loads. As a result, the fender will have a shorter collapsing length and, thus, improved stability.
A drawback of the above-mentioned fenders is that they have unsatisfactory stability when subjected to oblique loads. This is a problem since ships, when berthing, to a great extent strike against the fenders at an oblique angle, which means that the shock-absorbing end of the fender is laterally displaced relative to the fender fastening end which is fixedly secured, for instance, to a quayside.
According to U.S. Pat. No. 3,948,500, attempts have been made to solve this problem by means of a frustoconical fender with improved lateral stability. However, this fender has very thick walls, which makes the consumption of material great.
The object of the present invention is to provide a fender which is improved over prior-art technique.
A special object of the invention is to provide a fender with improved deformation properties when subjected to uneven loads.
One more object of the invention is to provide a strong fender with a reduced consumption of material.
According to the invention, these objects are achieved by the fender of the type described by way of introduction being given the features that are evident from claim 1. Preferred embodiments are defined in the dependent claims.
The inventive fender utilizes a deformation portion which on at least one surface is provided with projections and recesses having such a shape and location that they can engage with each other in a comblike manner during deformation of the fender. As the fender is being deformed, the projections engage in the recesses and provide locking of the fender. Thus, the fender cannot be deformed in the lateral direction and will have improved stability when subjected to oblique loads and shearing load.
According to an embodiment of the invention, the projections and recesses are located on an outwardly directed surface portion of the deformation portion. The projections and recesses may instead be positioned on an inwardly directed surface portion of the deformation portion, or on both an inwardly directed and an outwardly directed surface portion of the deformation portion.
According to an embodiment of the invention, the deformation portion of the fender has first and second conical hollow portions, whose narrow ends are joined with each other, and the projections are arranged with interspaces forming the recesses, the first and second conical portions being arranged relative to each other in such manner that the projections on one frustoconical portion engage in the recesses on the other frustoconical portion. This design makes it possible to provide the desired locking in a simple and safe manner, while at the same time the manufacture of the fender can be made very rational.
In an embodiment of the inventive fender, the first conical portion is made of a material with essentially higher hardness than the second conical portion. This gives the possibility of controlling the deformation of the fender when subjected to loads. The softer conical portion is then pressed together before deformation of the harder conical portion begins.
According to another embodiment, the fender is designed as at least two parallelepipedal fender legs. This is an alternative way of making a strong fender according to the invention.
The parallelepipedal fender legs advantageously have V-shaped projections. During deformation of the fender, the V-shaped projection will engage in the recess between the legs of the V, which ensures a good stabilizing locking.
The deformation portion of the tender is preferably made of an elastomeric material, which gives the fender the desired stability and flexibility.